SANTA ANA, Calif. (AP) — A 19-year-old man was charged Friday with shooting his parents to death and trying to kill two of his siblings inside their luxury Southern California home in a complex case that took investigators weeks to unravel.

Ashton Sachs, who enrolled at a college in Washington state last fall, is being held without bail in an Orange County jail on two counts of murder with special circumstances and two counts of attempted murder. If convicted, Sachs could face the death penalty.

The arrest comes after Bradford Sachs, 57, and Andra Sachs, 54, were fatally shot in their nearly 9,000-square-foot San Juan Capistrano home on Feb. 9. Sachs also shot and critically injured his 8-year-old brother and fired at one of his two sisters who were home at the time, but missed hitting her and then fled the scene, prosecutors said.

Investigators combed the home but initially found no signs of a break-in and little evidence leading them to a suspect. After a monthlong probe, investigators arrested Sachs in San Diego on Thursday and said they have recovered what they believe to be the murder weapon.

Investigators have yet to identify a motive, but Orange County prosecutors say Sachs returned from Seattle planning to kill his family. Early in the morning of Feb. 9, he shot his parents while they slept in their bedroom and shot his younger brother, paralyzing him, the district attorney's office said in a statement.

Bradford and Andra Sachs, who had five children, filed for divorce more than a decade ago but continued to live and conduct business together. Over the years, they faced a number of lawsuits related to their business dealings, according to the Orange County Register.

Montano said investigators spoke with Ashton Sachs "at length" after his arrest. Montano declined to reveal what Sachs told them.